Process for removing metallic soap from lubricating emulsions



A ril 17, 1934. R Q AM AL 1,955,522

PROCESS FOR REMOVING METALLIC SOAP FROM LUBRICATING EMULSIONS Filed June 27, 1931 (FYFP 0F SOL VENT I N V EN TORS. Faber! G ZUzl/z'ams. Howard MFA/55a B Y /6rv/LPWEV M ATTORNE 5.

Patented Apr. 17, 1934 PROCESS FOR REMOVING METALLIC SOAP FROM LUBRIl-DATING EMULSIONS Robert C. Williams and Howard W. Russell, lumbus, Ohio, assignors to The Ironsides Company, Columbus, Ohio, a corporation of Ohio Application June 27, 1931, Serial No. 547,406

3 Claims.

Our invention relates to a process for removing metallic soap from lubricating emulsions. It has to do particularly with a novel method of removing copper soaps from aqueous copper wire 5 drawing lubricating emulsions, although it is not necessary limited thereto.

In wire drawing and other forming operations upon metals, it is frequently desirable to utilize a lubricating emulsion to facilitate the forming 0 operations. Thus, in the drawing of copper wire by modern high-speed apparatus, it is customary to utilize a lubricating emulsion for lubricating the dies to facilitate the drawing operation. It is common practice to utilize a wet lubricant over and over again and these lubricants ordinarily take the form or" aqueous emulsions of soap and animal or vegetable oil or fat. The repeated use of such a lubricant results in the gradual accumulation therein or" copper soap which results primarily from the combined influence or action of oxygen from the air and free fatty acid upon the particles of metallic copper which are produced by the abrading of the copper wire by the dies and capstans. These soaps, which may be copper oleate or copper stearate are undesirable for many reasons.

For one thing, the copper soap ordinarily holds finely divided metallic copper and this results in scoring of the wire being drawn. Under certain conditions, the collection of this copper soap in toe die angle may even cause breakage of the wire. Irrespective of the metallic copper particles which may be mechanically held in the copper soap, this copper soap may be as responsible as excess fat for sucking wherein the wire comes through the die under-size. Likewise, the abrasive action of the copper which is mechanically held in the copper soap apparently causes excessive capstan wear in machines where the lubricant solution is pumped onto the capstan. The copper soap even tends to reverse the type of emulsion, producing the water-in-oil type instead of the desirable oil-in-water type, which results in undesirable unstable emulsion conditions.

Removal of the copper by straining or filtration is impracticable because of the labor, equipment and attention required. At present, the common practice is to either discard the entire solution when its decreased utility makes this necessary or to remove the settled portion and the scum periodically after permitting the lubricant to stand in idle tanks.

The drawing of brass or bronze wire with high speed machinery produces a similar condition with the formation of zinc and tin as well as with copper soaps.

Our invention contemplates the removal of copper soaps and soaps of the type in question from the lubricant solution by means of a solvent for such soaps. We preferably use a solvent which is immiscible and which is not readily emulsifiable with the solution. This solvent is introduced as a superimposed layer upon the solution and serves to extract the copper soap or similar soap so that the removal of this solvent is accompanied by the removal of the soap.

To simplify the explanation of our process, we have shown in the accompanying drawing the usual type of apparatus for supplying a lubricant or coolant to a wire drawing apparatus, wherein:

The figure is a diagrammatic view or" a lubricant container equipped with a circulating apparatus and showing a layer of solvent superimposed upon a lubricant.

In the drawing the container may be designated l and is shown with a spigot 2 adjacent the upper end thereof by which the solvent may be drawn off from time to time. A conduit 3 extends from a substantial depth within the lubricant to a pump 4 which is in turn connected to a conduit 5 for conducting the lubricant to the wire drawing machine. A return conduit 6 preferably returns the lubricant from the wire drawing machine by gravity, having its outlet end at a point below the layer of solvent.

The body of the lubricant may be designated '7 and 8 designates metallic copper which has settled to the bottom of the container. The lubricant shown is a soap and tallow emulsion. Superimposed thereon is a layer of solvent, such as parafiin, this layer being designated 9.

In the removal of copper soap from soap and tallow emulsions, we preferably use paraffin wax, molten at the common operating temperatures of 150 to 160 F. Lower melting parafiin stocks may be used to advantage where operating temperatures are lower. Tests have shown that the paraflin was not emulsified under the conditions of gentle agitation which occur in actual practice, as where lubricant solutions in large reservoirs are circulated to a number of machines. It was also demonstrated that the stability of the emulsion was not adversely afiected, while the paraffin extracted relatively small quantities of the soap and tallow so that loss of the essential lubricant ingredients did not materially occur.

The amount of solvent necessary to effectively remove the copper soap which is formed depends on several factors such as the solubility of the copper soap in the solvent, the frequency of removal of used solvent and the rate at which the copper soap is formed. A sufficient quantity of solvent should be provided so that the layer is not disrupted by gentle agitation and so that this layer can be conveniently drawn off.

In the operation of a lubricating system of this type the metallic copper settles to the bottom of the lubricant container and the copper soap or other soap floats to the top. Where, as in our process, a layer of solvent has been superimposed upon this lubricant, the soap which floats to the top enters into solution with the layer of solvent. The layer of solvent may be drawn off from time to time and renewed as frequently as may be necessary under the conditions of operation.

It will be understood that the process is applicable for extracting water insoluble metallic soaps from aqueous emulsions such as are used in drawing or forming either copper, brass, bronze or similar metals and alloys. Likewise, it will be understood that the term metallic soaps as used in the claims of this specification is intended tov include all such metallic soaps.

Having thus described our invention, what we claim is:

1. A process for removing metallic soap from a lubricant emulsion containing particles of such metallic soap, which comprises superimposing upon such lubricant emulsion and in contact therewith, a layer of molten parafiin wax or paraffin wax stocks, so that when the metallic soap particles of said lubricant emulsion float upwardly therein and then into said molten paraflin wax or paraffin Wax stocks they will be dissolved thereby,

2. A process for removing metal soap from an aqueous lubricant emulsion which is used for lubricating purposes and which contains particles of metal soap, which comprises placing a layer of oil which is a solvent for the metal soap and which is immiscible with said emulsion and a layer of aqueous emulsion in superimposed relation to each other and in contact with each other, so that when the metal soap particles of said emulsion move into said oil layer they will be dissolved thereby.

3. A process forremoving metal soap from an aqueous lubricant emulsion which is used for lubricating purposes and which contains particles or" metal soap, which comprises superimposing upon said aqueous lubricant emulsion and in contact therewith, a layer of oil which is a solvent for the metal soap and which is immiscible with said lubricant emulsion in quantity such that the layer is not disrupted by gentle agitation and can be conveniently drawn off, so that when the metal soap particles of said emulsion move into said oil layer they will be dissolved thereby.

ROBERT C. WILLIAMS. HOWARD W. RUSSELL. 

